Renesas RL78 Series Application Note

RL78 Family VDE Certified IEC60730/60335 Self Test Library
R01AN0749EG0201 Rev.2.01 Page 45 of 50
Mar 04, 2014
6.1.4 I/O Port SFR Protection
This is a write protection feature that prohibits a write to the SFR registers. No error is generated if a write
occurs, but the write operation does not change the state of the registers involved.
Please note that the data port register (Pxx) cannot be protected.
The protection can be turned off, if a change is required for the SFR registers or for safety reasons the SFR
settings are refreshed by the application.
The following I/O port SFR registers can be protected with this function
PMxx, PUxx, PIMxx, POMxx, PMCxx, ADPC, and PIOR
Pxx cannot be guarded.
The Port I/O SFR registers can be guarded by the “GPORT” bit as shown in figure 24 below
Figure 24 I/O Port SFR Guard Protection

Renesas RL78 Series Specifications

General

Brand	Renesas
Model	RL78 Series
Category	Computer Hardware
Language	English